Role of m6A mRNA methylation in Neuroblastoma Research efforts over the last thirty years have provided widespread evidence of epigenetic dysregulation in cancer, in which DNA methylation plays a critical role in tumor growth and survival. Drugs that alter DNA methylation by inhibiting the DNA methyltransferases (MTase) are used clinically to treat various malignancies. It is emerging that mammalian messenger RNAs (mRNAs) are also subject to various posttranscriptional modifications including m6A methylation. Our goal is to map the N6-methyladenosine (m6A) ?epitranscriptome? in the aggressive pediatric cancer neuroblastoma (NB) and to explore the molecular and cellular role of the m6A methyltransferase METTL3 in NB cells. Using an established protocol we will map m6A throughout the transcriptome of human NB cell lines, and in parallel adapt and apply the approach to the analysis of primary tumors from a well-defined NB mouse model before applying the optimized method to investigate m6A profiles in human NB tumor samples. Our preliminary inspection of published microarray datasets reveal that METTL3 mRNA expression is elevated in a subset of NB tumors and that high METTL3 expression significantly correlates with poor patient survival. We will measure for the first time METTL3 protein expression in tumors. The molecular and cellular role of METTL3 in human NB cells will be investigated to characterize the possible oncogenic function of METTL3 in NB cancer cell biology. This work will provide the first transcriptome-wide map of m6A in any tumor type, will globally identify direct METTL3 target messenger RNAs (mRNAs), uncover the widespread impact of m6A and METTL3 in controlling mRNA translation, and will establish METTL3 as a possible therapeutic target for the future treatment of NB and other cancers. Overall, this innovative proposal will establish methods for analyzing the m6A epitranscriptome in tumors and will have a major impact on determining the importance of the field of epitranscriptomics to understanding cancer biology.